/*
  *   Copyright (c) 1998, Regents of the University of California
  *   All rights reserved.
  *   Redistribution and use in source and binary forms, with or without
  *   modification, are permitted provided that the following conditions are met:
  * 
  *       * Redistributions of source code must retain the above copyright
  *         notice, this list of conditions and the following disclaimer.
  *       * Redistributions in binary form must reproduce the above copyright
  *         notice, this list of conditions and the following disclaimer in the
  *         documentation and/or other materials provided with the distribution.
  *       * Neither the name of the University of California, Berkeley nor the
  *         names of its contributors may be used to endorse or promote products
  *         derived from this software without specific prior written permission.
  * 
  *   THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
  *   EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  *   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  *   DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
  *   DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  *   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  *   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  *   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  *   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */



package org.demis.elf.ddlreader;

import java.util.Stack;
import org.demis.elf.Schema;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 *
 * @author <a href="mailto:demis27@demis27.net">Stéphane Kermabon</a>
 */
public class SchemaStackHandler extends DefaultHandler {

    private Stack<StackableHandler> stack = new Stack<StackableHandler>();

    private Schema result;

    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
        
        if (qName.equals("schema")) {
            SchemaHandler schemaHandler = new SchemaHandler(qName);
            stack.add(schemaHandler);
        }
        else if (qName.equals("table")) {
            TableHandler tableHandler = new TableHandler(qName);
            stack.add(tableHandler);
        }
        else if (qName.equals("column")) {
            ColumnHandler columnHandler = new ColumnHandler(qName);
            stack.add(columnHandler);
        }
        else if (qName.equals("primaryKey")) {
            PrimaryKeyHandler primaryKeyHandler = new PrimaryKeyHandler(qName);
            stack.add(primaryKeyHandler);
        }
        else if (qName.equals("foreignKey")) {
            ForeignKeyHandler foreignKeyHandler = new ForeignKeyHandler(qName);
            stack.add(foreignKeyHandler);
        }
        else if (qName.equals("index")) {
            IndexHandler indexHandler = new IndexHandler(qName);
            stack.add(indexHandler);
        }
        else if (qName.equals("columnRef")) {
            ColumnReferenceHandler columnReferenceHandler = new ColumnReferenceHandler(qName);
            stack.add(columnReferenceHandler);
        }
        else if (qName.equals("referencedColumn")) {
            ReferencedColumnHandler referencedColumnHandler = new ReferencedColumnHandler(qName);
            stack.add(referencedColumnHandler);
        }
        else if (qName.equals("uniqueConstraint")) {
            UniqueConstraintHandler uniqueConstraintHandler = new UniqueConstraintHandler(qName);
            stack.add(uniqueConstraintHandler);
        }
        if (qName.equals(stack.peek().getQName())) {
            stack.peek().startElement(uri, localName, qName, attributes);
        }
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        if (!stack.empty()) {
            if (qName.equals(stack.peek().getQName())) {
                StackableHandler handler = stack.pop();
                handler.endElement(uri, localName, qName);
                if (!stack.empty()) {
                    stack.peek().addObject(handler.getResult());
                }
                else {
                    result = (Schema)handler.getResult();
                }
            }
        }
    }

    public Schema getResult() {
        return result;
    }


    
}
